Michael S. Tsirkin
2009-Nov-04 15:52 UTC
[PATCHv8 0/3] vhost: a kernel-level virtio server
Ok, I think I've addressed all comments so far here. Rusty, I'd like this to go into linux-next, through your tree, and hopefully 2.6.33. What do you think? --- This implements vhost: a kernel-level backend for virtio, The main motivation for this work is to reduce virtualization overhead for virtio by removing system calls on data path, without guest changes. For virtio-net, this removes up to 4 system calls per packet: vm exit for kick, reentry for kick, iothread wakeup for packet, interrupt injection for packet. This driver is pretty minimal, but it's fully functional (including migration support interfaces), and already shows performance (especially latency) improvement over userspace. Some more detailed description attached to the patch itself. The patches apply to both 2.6.32-rc6 and kvm.git. I'd like them to go into linux-next if possible. Please comment. Changelog from v7: - Add note on RCU usage, mirroring this in vhost/vhost.h - Fix locking typo noted by Eric Dumazet - Fix warnings on 32 bit Changelog from v6: - review comments by Daniel Walker addressed - checkpatch cleanup - fix build on 32 bit - maintainers entry corrected Changelog from v5: - tun support - backends with virtio net header support (enables GSO, checksum etc) - 32 bit compat fixed - support indirect buffers, tx exit mitigation, tx interrupt mitigation - support write logging (allows migration without virtio ring code in userspace) Changelog from v4: - disable rx notification when have rx buffers - addressed all comments from Rusty's review - copy bugfixes from lguest commits: ebf9a5a99c1a464afe0b4dfa64416fc8b273bc5c e606490c440900e50ccf73a54f6fc6150ff40815 Changelog from v3: - checkpatch fixes Changelog from v2: - Comments on RCU usage - Compat ioctl support - Make variable static - Copied more idiomatic english from Rusty Changes from v1: - Move use_mm/unuse_mm from fs/aio.c to mm instead of copying. - Reorder code to avoid need for forward declarations - Kill a couple of debugging printks Michael S. Tsirkin (3): tun: export underlying socket mm: export use_mm/unuse_mm to modules vhost_net: a kernel-level virtio server MAINTAINERS | 9 + arch/x86/kvm/Kconfig | 1 + drivers/Makefile | 1 + drivers/net/tun.c | 101 ++++- drivers/vhost/Kconfig | 11 + drivers/vhost/Makefile | 2 + drivers/vhost/net.c | 633 +++++++++++++++++++++++++++++ drivers/vhost/vhost.c | 970 ++++++++++++++++++++++++++++++++++++++++++++ drivers/vhost/vhost.h | 158 +++++++ include/linux/Kbuild | 1 + include/linux/if_tun.h | 14 + include/linux/miscdevice.h | 1 + include/linux/vhost.h | 126 ++++++ mm/mmu_context.c | 3 + 14 files changed, 2012 insertions(+), 19 deletions(-) create mode 100644 drivers/vhost/Kconfig create mode 100644 drivers/vhost/Makefile create mode 100644 drivers/vhost/net.c create mode 100644 drivers/vhost/vhost.c create mode 100644 drivers/vhost/vhost.h create mode 100644 include/linux/vhost.h
Michael S. Tsirkin wrote:> Ok, I think I've addressed all comments so far here. > Rusty, I'd like this to go into linux-next, through your tree, and > hopefully 2.6.33. What do you think?I think the benchmark data is a prerequisite for merge consideration, IMO. Do you have anything for us to look at? I think comparison that show the following are of interest: throughput (e.g. netperf::TCP_STREAM): guest->host, guest->host->guest, guest->host->remote, host->remote, remote->host->guest latency (e.g. netperf::UDP_RR): same conditions as throughput cpu-utilization others? Ideally, this should be at least between upstream virtio and vhost. Bonus points if you include venet as well. Kind regards, -Greg -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 267 bytes Desc: OpenPGP digital signature Url : http://lists.linux-foundation.org/pipermail/virtualization/attachments/20091104/172b2ec0/attachment.pgp